Crowd and retract mechanism



Aug. 17, 1943. B. s; FERGUSON 2,326,935

CROWD AND RETRCT MECHANISM Filed sept. 4, 1941 2 sheets-sheet 1/NvE/VTOR BERLIN S. Fsweuso/v @Y @and (Af/m A@ Hm Avramvsx Aug. 17,1943. B. s. FERGUSON CROWD AND RETRACT MECHANISM Filed Sept. 4, 1941 2Sheets-Sheet 2 /NvEN-ron.- Bem/N 3. FRGUSON BY WW ATTORNEY.

Patented Aug. 17, 1943 CROWD AND RETRACT MECHANISM Berlin S. Ferguson,Ravenna, Ohio, assignor' to l Byers Machine Company, Ravenna, Ohio, a

corporation of Ohio Application September 4, 1941, Serial No. 409,593 1claim. (c1. 2st-isi) This invention relates to a crowd and retractmechanism for power shovels. It is the general practice in this art'todrive the crowd and retract drum or sprocketin either direction byapplication of the same amount ofl power, but at lower speed to giveadequate mechanical advantage for the heavy work of crowding, and athigher speed for the retracting motion. Various gear arrangements areknown for the purpose. However, in shovel construction space is at apremium, and the machinery must stand up to very rough hard service. Thelubrication problem is diilic'ult and important both on account of theheavy duty required and because of the atmosphere of dust and grit whichgenerally characterizes digging operations.

In view of these requirements, the purpose of the present invention isto provide such a mechanism in more compact and sturdy construction,more readily accessible for service and repairs, stronger and moredurable, more easily clutched and unclutched for operation, constantlyand easily lubricated, protected from dirt, and generally more efficientthan previous mechanisms of this character.

In the accompanying drawings which show a preferred embodiment of theprinciples of my invention,

Fig. 1 is a vertical central section taken 1ongitudinally of the shaft,with certain parts in elevation, looking towards the front of the shoveldeck;

Fig. 2 is a transverse view approximately as indicated by line 2--2 ofFig. 1; and

Fig. 3 is a diagrammatic right side elevation showing the relation ofthe crowd-retract drum to other parts of the shovel mechanism.

Referring to the drawings, it will be understood that in accordance withthe usual practice in power shovel construction, the mechanism includesan assembly of drums, clutches, brakes, gears, etc., carried by andconnecting a number .of shafts transverse to the shovel deck and alltaking power from some prime mover, usually an internal combustionengine. Only so much of the complete operating mechanism is shown in thepresent application as is necessary to illustrate the immediatesurroundings of the present invention.

In one practical organization of the mechanical assembly, such asdiagrammatically indicated in Fig. 3, an engine not shown drives ajackshaft II by a chain I2. A pinion I3 on the jackshaft meshes with alarge gear I4 on the hoist shaft I5, which in turn meshes with the largegear I6 (hereafter sometimes referred to as the driving gear) keyed tothe crowd-retract shaft I'I. A hoist drum such as |5A with hoist lineISB thereon is mounted on and driven from shaft I5. The assembly issupported from the shovel deck I 8 by appropriate side frames such as I9, I9' and run in suitable bearings suchI as 20, 2|, 22 and 23.

I'he crowd-retract drum 24 is rotatably carried, as by bearings 25 and26, upon the shaft Il. A clutch 21 and collar 28 are fast to the shaftI1 at opposite `ends of the drum 24, and a stuffing box 29 surrounds oneend of the shaft, all for purposes to be described hereafter. As amatter of convenience for assembly purposes, the shaft Il is formed todifferent diameters, largest in the center, successively diminishingoutwardly. Since the shaft Il rotates continu' ously in the directionindicated by arrows in Figs. 1 and 3 during the operation of the shovel,setting the clutch 2l rotates the drum 24 directly with the shaft tocrowd `the dipper or-other instrumentality by the driving cables 30,whereas release of the clutch and actuation of certain gearings drivesthe drum 24 oppositely and faster, to retract.

The drum 24 has an extended circumferential flange at each end, 3| atthe right, 32 at the left. The ange 3| surrounds the clutch 2l, which inthe present illustrative embodiment is of the pneumatic type, with innertube 33 actuated by compressed air admitted at the connection 34 throughstuiiing box 29, and reaching the clutch through a shaft passage 35 andhose 36. A tread 3l bears against the inner surface of flange 3| whenair is admitted at 34, thereby carrying the drum 24` directly with theshaft to crowd the dipper, as previously stated.

The ange 32 is surrounded by a brake band 38 which, when set, holds thedrum 24 against movement. v

The gearing at the left end of the drum comprises a bevel gear 39projecting leftward from the drum, a series of pinions 40 carried by acage 4|, and a crown gearv 42 fast to the collar 28. As a matter ofconvenient construction, the gear 39 may be formed on the enlarged endof a sleeve 43 keyed in the structure of the drum 24, the crown gear 42may be riveted to the enlarged recessed outer end 44 of the collar 23,and the pinions 40 turn on heavy pins 45 in bosses 46 in the cage 4|.

The cage 4I is rotatable on the shaft Il by a suitable bearing, thepreferred construction shown comprises a hub 4l partly inside but clearof the recessed end 44 of collar 28, a solid web 48 to which the housing48 is bolted, and a circumferential flange 50. A brake, indicated by theband can be set to hold the cage, in which situation the drum 24 isdriven backwards and faster through the crown gear 42, pinlons 40 andbevel gear 88, thus retracting the clipper by cables 30. It will ofcourse .be understood that the clutch 21 and the brake 38 are bothreleased during retraction.

The lubricating and dust-proofing features of my invention will now bedescribed.

At the left end the drum and gear system is sealed against ingress ofdust and egress of oil or grease by sealing rings `such as 52 and 53 andtheir associated parts. external to the cage hub 41. The inner end ofthe housing 49 overlaps a leftwardly-projecting inner flange 54 and thespace here is closed by an oil seal 55. Lubricant which is supplied at aflllingplug '56 cannot escape at 52, 53 or 55, but itv can pass throughthe rollers of bearings 25 and 26. The drum 24, as

usual,has large interior recesses, to reduce weight and for otherpurposes, and is generally made in sections, bolted together but notoil-tight. To prevent access of oil and grease to the drum interior, alining tube 51 is used. The gear sleeve 43 is tight Within the drum, andthe tube 51 is tight within the sleeve; thus lubricant is not lostbetween these members. A seal outside the bearing 26 prevents escape oflubricant at the right end; thus the entire system of retract gears anddrum bearings can be run in a bath of lubricant and protected from dustand dirt.

To ,recapitulatez The gear housing 49 being filled with lubricant andthe plug 56 closed, power is applied and the shaft I1 rotates, alwaysclockwise as seen in Fig. 3 and at constant speed. The drum 24 remainsstationary, held if desired by the brake 38. To crowd the shovel intoits work the brake 38 is released and the clutch 21 is set, therebycarrying the drum around with the' shaft. During this operation the gearcage brake 5| is off so that the cage can rotate and there is no drivingeffect between gears 42 and 39.

When the clutch is released the drum again stands stationary on therotating shaft, held, if necessary, by the brake 38. To retract, thebrake 5| is set, whereby the cage 4| is held fast and the pinions 40transmit power from the crown gear 42, which is keyed to the shaft, tothe bevel gear 39, and thus drive the drum 24 counterclockwise, and at ahigher speed than that of the shaft, because gear 39 is smaller than 42.When the brake 5I is released the cage 4i again rotates freely and nopower goes to the drum.

Having thus described a preferred embodiment of my invention, it is tobe understoodV that changes may be made in the details of its embodimentwithout departing from the principles employed. For example, thewell-known practice of using a sprocket and chain on the drum instead ofthe cables may be followed, other types of clutch and of brake might beused, and so on.

In the claim the term drum includes sprocket or other dri'ing connectionmounted on the shaft and having flexible elements such as chains orropes connecting to the implement being' crowded and retracted,superposed on the drum or otherwise, such equivalents or substitutes fordrums being well known in the art.

I claim:

In a crowd-retract mechanism of the type comprising a driven shaft, adrum, and bearings at each end of said drum carrying said drum rotatablyon said shaft, circumferential flanges on each end of said drum oflarger diameter than said drum extending axially outwardly from saiddrum; a clutch within one of said flanges adapted selectively to connectsaid drum to said shaft to rotate directly therewith; and a gear trainpartly shrouded by the other said flange, said gear train comprising abevel gear fast to the end of said drum surrounding said shaft butradially clear therefrom, a cage rotatable on said shaft, journalscarried by said cage disposed radially to said shaft but disposed at anangle to the shaft axis, and a crown gear of greater diameter than saidbevel gear fast to said shaft, pinions on said journals connecting saidcrown and bevel gears, a sleeve fast on said shaft nested at one endwithin but rotatably clear of said bevel gear, the nested end of saidsleeve constituting an end retention for a bearing of said drum, saidcrown gear being secured to said sleeve, said cage including a bearingon said shaft partly nested within but rotatably clear of said crowngear sleeve, and means for selectively holding said cage againstrotation.

BERLIN S. FERGUSON.

